Test Voltages for Cables
3
TES T V OLTAGES FOR M V , HV & EH V C ABLES Test Voltages for Medium Voltage Cables 1 2 3 4 5 6 7 8 Rated Voltage U Highest voltage for equipment Um Value of Uo for determination of test voltages Uo Routine test 3.5 Uo Partial Discharge 1.5 U o Sample Test 4 U o Impulse Test Voltage Test fo r 15 minutes kV kV kV kV KV KV kV kV 6 10 15 20 30 7.2 12 17.5 24 36 3.6 6 8.7 12 18 12.5 21 30.5 42 63 5.4 9 13 18 27 - 24 35 48 72 60 75 95 125 170 12.5 21 30.5 42 63 PDF created with pdfFactory Pro trial version www.pdffactory.com
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Transcript of Test Voltages for Cables
8/8/2019 Test Voltages for Cables
http://slidepdf.com/reader/full/test-voltages-for-cables 1/3
TEST VOLTAGES FOR
MV, HV & EHV C ABLES
Test Voltages for Medium Voltage Cables
1 2 3 4 5 6 7 8
Rated Voltage
U
Highestvoltage forequipment
Um
Value of Uo for
determinationof test
voltages
Uo
Routinetest
3.5 Uo
PartialDischarge
1.5 Uo
SampleTest
4 U o
ImpulseTest
Voltage Testfo r
15 minutes
kV kV kV kV KV KV kV kV
6
10
15
20
30
7.2
12
17.5
24
36
3.6
6
8.7
12
18
12.5
21
30.5
42
63
5.4
9
13
18
27
-
24
35
48
72
60
75
95
125
170
12.5
21
30.5
42
63
PDF created with pdfFactory Pro trial version www.pdffactory.com
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TEST VOLTAGES FOR
MV, HV & EHV C ABLES
Test Voltage for Ext ra High Voltage cables
1 2 3 4 5 6 7 8 9Rated
Voltage
U
Highestvoltage forequipment
Um
Value of Uo for
determination
of test voltages
Uo
Voltage test
Volt-
Dura-
Age1) tion1)
Partialdischarge
test
1.5 Uo
Heatingcycle
voltage test
2 Uo
Impulsevoltage test
Voltage test after
impulse voltage test
2Uo
Switchingimpulse Voltage
test
kV kV kV kV min kV kV kV KV K V
220 to 230 245 127 318 30 190 254 1050 254 -
275 to 287 300 160 400 30 240 320 1050 320 850
330 to 345 362 190 420 60 285 380 1175 380 950
380 to 400 420 220 440 60 330 440 1425 440 1050
500 550 290 580 60 435 580 1550 580 11751) A threshold limit of 27 MV/m to 30 MV/m should not be exceeded for some insulations (as specified by the supplier), in order
to avoid any possible weakening to the insulation prior to delivery which might later cause a failure in service . At the voltagetest of (4), for rated voltage 330 kV to 500 kV, the voltage is lowered, combined with a longer testing time in order to avoid
too high stresses. For insulations where a threshold limit is not a problem, the supplier may increase the test voltage and
reduce the testing time. However, the duration should be at least 30 min.
Subject to agreement between manufacturer and purchaser, the voltage test of (4) may be replaced by a test at lower voltageand longer duration even if the maximum stress in the insulation is lower than 30 MV/m. However, the voltage level shall notbe below 1.5 Uo and duration not longer than 10 h.
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